Car bottomed furnace



March 29, 1960 H. w. BODEN CAR BOTTOMED FURNACE 3 Sheets-Sheet 1 FiledApril 19, 3.957

INVENTOR. HARRY vv. BODEN March 29, 1960 H. w. BODEN CAR BOTTOMEDFURNACE 3 Sheets-Sheet 2 Filed April 19, 1957 INVENTOR. jDDEN HARRY W.

March 29, 1960 H. w. BODEN CAR BOTTOMED FURNACE 3 Sheets-Sheet 3 FiledApril 19, 1957 l l I I l l J 22 w,8

INVENTOR.

W. BODEN HARRY ATT ORNEY CAR BOTTGMED FURNACE Harry W. Boden, Toledo,Ohio, assignor, by mesne assignments, to Midland-Ross Corporation,Cleveland, Ohio, a corporation of Ohio Application April 19, 1957,Serial No. 653,786 Claims. (Cl. 263-28) This invention relates tofurnaces and more particularly to annealing furnaces of the removablebottom type.

Furnaces of the type to which the removable furnace bottom of theinvention are especially applicable are stationary annealing furnaceswhich have doors for taking work into and out of the furnaces incontrast to furnaces of the bell type which are lowered over worksupporting bases and subsequently raised after the heat treating processhas been completed. In such stationary annealing furnaces it is highlydesirable, particularly where it is desired to have controlledatmosphere, to have gas-tight seals between the stationary walls of thefurnaces and the removable furnace bottoms and especially to havegastight seals around the doors on the furnaces. Prior removable bottomtype furnaces have not been provided with satisfactory gas-tight sealsfrom the standpoint of the efliciency of the seals themselves and alsofrom the standpoint of the ease of operation of the seals which, ofcourse, must be broken when the furnace bottoms are removed.

It is, accordingly, the principal object of this invention to provide animproved removable bottom furnace.

Another object of the invention is to provide, in a removable bottomfurnace, efficient and easily operable seals for preventing leakage ofgas from the furnace.

More specific objects and advantages are apparent from the followingdescription, in which reference is bad to the accompanying drawingsillustrating a preferred embcdiment of the invention.

In the drawings:

Figure I is a longitudinal, fragmentary, vertical sectional view throughan annealing furnace embodying the invention, showing the position ofthe various parts during an annealing cycle;

Figure II is a transverse, vertical sectional view taken along the lineIIII of Figure I looking in the direction indicated by the arrows;

Figure III is an enlarged, fragmentary, perspective view of thegas-tight seal operating mechanism which is illustrated in Figures I andII;

Figure IV is a perspective view of one of the rod supports on theremovable furnace bottom for the gas-tight seal operating mechanismwhich is shown in Figure III; and

Figure V is a schematic plan view of the gas-tight seal mechanism whichcompletely encloses the removable furnace bottom. These specificdrawings and the specific description that follows merely disclose andillustrate the invention and are not intended to impose limitations uponthe claims.

Referring to Figures I and II, the annealing furnace 1 includes a roof 2that is supported by stationary side walls 3 which also supporthorizontal bottom ledges 4 that run the length of the furnace. Thefurnace bottom ledges 4 are spaced an appreciable distance apart so thatthe furnace is essentially bottomless. The furnace is heated by anysuitable and well known means, not shown,

the heated gases being circulated by motor 5 operated side edges andwhich are raised and lowered by means of' ordinary hydraulic cylinder ormotor operated door hoists S. When a door 7 is raised, a removablefurnace bottom 10 comprising a car 11 is moved into place between thestationary spaced furnace bottom ledges 4. By way of' illustration,there is shown a charge of work W on the car 11 within the furnace 1which is being heat treated. The car 11 includes a refractory-coveredframe 12 that supports a rigid metallic framework 13 upon which the workW is stacked.

Rails 14. having their upper surfaces about flush with the floor 15 thatsupports the furnace serve as tracks for flanged wheels 16 on the car11. The wheels 16 at the left end of the car as viewed in Figure I arechain-drive connected to a motor 17 that is carried on an extension 18of the car 11 as an integral part thereof, the chain drive beingindicated generally at 19. Work W to be heat treated is loaded on thecar 11 exteriorly of the furnace and then is moved in from, for example,the left-hand side of the furnace as viewed in Figure I. After the heattreating is finished, the doors 7 are opened, the car 11 within thefurnace is moved to the right out of the furnace and another carimmediately moved into the furnace from the left to save time and lossof heat.

The car frame 12 also functions to support gas-tight seal mechanismwhich includes a trough 20 having a generally H-shaped form in plan asillustrated schematically in Figure V, the H-shaped trough 2thcompletely enclosing the car 11 on all sides and being selectively,vertically positionable by means of an elevator device hereinafterdescribed. Depending from the horizontal furnace bottom ledges 4 arevertical sealing flanges 21 (Figure II) which as shown in Figure V haveangle abutment faces 22 in juxtaposition with the doors on which faces22 the bottom portions of the vertical seals 8 on the doors 7 bear.Depending from the refractory-covered frame 12 of the car 11 arevertical sealing flanges 23 which, as shown in Figure V, have arectangular form in plan, the sealing flanges 21 on the furnace beingstationary and the sealing flanges 23 being movable along with the car11. The vertical sealing flanges 21 and 23 cooperate with the trough 20in its elevated position as shown in Figure II to provide a gas-tightseal between the removable furnace bottom 10 comprising the car 11 andthe furnace bottom ledges 4 when the trough 20 is filled with a suitablesealing means such as sand, water or oil 24. The openings in the sidewalls 3 which are closed by the doors 7 are sealed around their edges bythe seals 8 on the doors which cooperate with the upper edges and sideedges of the doorways and which extend down into the trough 20 asillustrated in Figure I.

Selective vertical positioning of the trough 20 is accomplished by meansshown in detail in Figures III and IV, such means comprising a pluralityof links 25, only one pair of which is shown in Figure III, which arepivoted on horizontally extending rods 26, carried by the car frame 12,when the links are in a first or lowered position and which are pivotedat 27 on bases or channels 28 when the links are in a second or raisedposition, the trough 20 being pivotally connected at 29 to the upper endof the links and the channels 28 being pivotally connected at 27 to thelower end of the links. The links 25 are shown in their lowered positionin Figure III and in their raised position in Figures I and II.

Force applied to the trough 20 by any suitable means in the directionindicated by the arrow in Figure III causes the links 25 to turnclockwise about the axes of 3 the rodsjfi until; th =,-..channels 28touch the .floor 15. This is accomplished with little force. Since th echannels 28 then become stationary on the floor, the links then pivotabout the pivots 27 lifting the sealing means filledtroughzil withrelatively great forceinto cooperating relationsh ip with thesealingflanges 2 1 and 2 3z, with the lower edges of thev doors "7 andwith the, lower portions of the vertical door seals 8, as shown inFigures I and'II. As the links 25 ;turn clockwiseabout thepivots 27, thelinks because of their notchlrtllconnection with the rods 26arepermitted to move. away fromthe rods a small distance. Such force,for example, may be applied to the; trough 2% by power supplied from thehydraulic cylinders or by the motors that operate the door. hoists Thehoists 9 .include driven cha'ns 31 wh ich.may be. driyingly butdetachably connected. to the trough 20 through an ordinary gear reducerwhich may be geared down to give about a 12:1 to 24: 1- mechanicaladvantage. With a 12:1 mechanical advantage using such an arrangement,the doors '7 would move down, for example, six feet andthe trough 29would move up six inches. Alternatively, the force might be. suppliedthrough a clutch device by the motor 17 on the car or even by hand.

After the annealing operation, the direction of the force applied to thetrough 20 is reversed, the links 25 turning about pivots 27 in acounterclockwise. direction as viewed in Figure III until the channels23 are lifted clear ofthe floor i and the notches 30 in the links 25 fitsnugly on the rods 26, as shown in Figure III. In such position, i.e.,the lowered position, the trough 20 more or less counterbalances thechannels 28 and the trough and the channels ride in neutral equilibriumon the rods 26 as the truck 11 is moved into or out of the furnace.

In summary, in operation, the furnace doors '1' are opened and theremovable furnace bottom comprising the car 11 is moved on rails 14 intothe furnace, work W to be heat treated being loaded onto the carexteriorly of the furnace. At this time the sealing means filledtrough20 is in lowered position and is counterbalanced by the channels 28 asillustrated in Figure III. The doors 7 are then lowered and force isapplied to the trough 20 in the direction indicated by the arrow in Fig:ure III. At first the links 25 to which the trough 20 is rockablyconnected turn about the axes of the rods 26. This raises the trough andlowers the channels 28 until the channels rest upon the floor 15. Thenthe links. 25 turn about the pivots 27. This raises the trough furtheruntil lower portions of the sealing flanges 21 and 23 on the. car 11 andon the furnace bottom ledge Q, respec; tively, the lower edges of thedoors 7 and thelower portions of the vertical door seals 8 are submergedin the sealing means, such as water, oil or sand, in the trough Thetrough completely encloses the car. and efiiciently prevents escape ofgas from the furnace, the seal being not only, a good one but also beingone that is easily made and broken. 7

After the annealing cycle is completed, the doorsv 7 are raised andforce is applied to the trough 20 in the opposite direction. This lowersthe trough, breaking the gastight seal, and raises the channels 23 clearof the floor 15. The car 11 then is free to move on its wheels. 16 alongthetrack 14 out of the furnace.

It is to be understood that the foregoing detailed de: scription isgiven merely by way of illustration and that variations may be madetherein without departing, from the spirit of the invention.

1 claim:

1. A furnace supported on a floor. comprisingin cornbination, stationarywalls, a removable bottom, sealing members on the stationary walls andon the removable furnace bottom, a sealing means filled-trough carriedby the removable furnace bottom, and means for. selectively raising andlowering the trough into and out of, respectively, cooperatingrelationship with the sealing members, said means for selectivelyraising and lowering the trough including rigid members carried by theremovable furnace bottom, a plurality of links having a first and asecond position, the trough being pivotally connected to the links, anda base rockably connected at pivot points on the links, the links intheir first position being pivoted on the rigid members at points on thelinks intermediate the trough and the base and the links in their secondposition being pivoted not o'n'the rigid members but at the pivot pointson the base, said base being carried by the links in their firstposition clear of the floor and being lowered onto the floor by the.links when the links are moved into their second position. Y

2. A furnace supported on a floor comprising, in combination,stationarywalls, a removable bottom, sealing flanges depending from thestationarywalls, said flanges having angle abutment faces facing theends of the furnace, additional sealing flanges depending from theremovable furnace bottom, a sealing means filled-trough carried-by. theremovable furnace bottom, and means for selectively. raisingand'loweringthe trough into and out of, respectively, cooperating relationship withthe sealing flanges, said means. for selectively raising and loweringthe trough including rigid members carried by the re movable furnacebottom, a plurality of linkshaving a, first and a 'secondposi'tion, thetrough being pivotally connected to the links, and a, basefrockablyconnected at pivot points on the links, the links in their firstposition being pivoted on the rigid members at points on the linksintermediate the trough and the. base and thelinks in their secondposition being pivoted not on the rigid members but at the pivot pointson the base, said base being carried. by the links in their firstposition clear of the floor and being lowered onto the fioor by thelinks when the links are moved into their second position. i

3. A' furnace supported on'a" fioor'comprising, in combination,stationary walls, a door on a wall, sealing means on, the door toprevent escape of gas around the top and the sides of the door, aremovable furnace bottom adapted to pass through the door, sealingmembers on the stationary walls. and on the removable furnace bottom, asealing means filled-trough carried by the removable furnace bottom, andmeans for selectively raising and lowering the trough into and out of,respectively, cooperating relationship with the bottom of the door andwith the sealing members, said means for selectively, raising andlowering the trough including rigid members. carried by the removablefurnace bottom, a plurality of links having a first and a secondposition, the trough being. pivotally connected to the links, and a baserocka bl y connected atpivot points 'onthe' links, the links in theirfirst position being pivoted on the'rigid members at points on the linksintermediate the trough and'the base and the links in their secondposition being pivoted not on the rigid members but at the pivot pointson the'base, said basebeing carried by the links in their first positionclear of the floor and being lowered onto the floor by the linkswhen thelinks are moved into their second position. l

4. A furnace comprising, in combination, stationary walls, a door on awall, sealing means on the door to prevent escape of gas around the topand the sides of the door, a removable furnace bottom adapted to passthrough. the door, sealing flanges depending from the stationary walls,said flanges having angle'abutment'faces facing and in juxtapositionwith'the door, whereby the sealing means on the door cooperates with theabutment faces when the. door. is closed, additional sealing flangesdepending fromvthe removable furnace bottom, a sealing meansfilled-trough carried by the removable furnace bottom, and means forselectively raising and lowering thetrough into and out of,respectively, cooperating relationship with the bottom of the door andwith the sealing flanges, said means for selectively raising andIOl/VET'. ing the trough including rigid members carried by theremovable furnace bottom, a plurality. of links pivoted on the rigidmembers, the trough being pivotally connected to the links at one sideof the rigid members, and a base pivotally connected to the links at theother side of the rigid members.

5. A furnace supported on a fioor comprising, in combination, stationarywalls, a door on a wall, sealing means on the door to prevent escape ofgas around the top and the sides of the door, a removable furnace bottomadapted to pass through the door, sealing flanges depending from thestationary walls, said flanges having angle abutment faces facing and injuxtaposition with the door, whereby the seahng means on the doorcooperates with the abutment faces when the door is closed, additionalsealing flanges depending from the removable furnace bottom, a sealingmeans filled-trough carried by the removable furnace bottom, and meansfor selectively raising and lowering the trough into and out of,respectively, cooperating relationship with the bottom of the door andwith the sealing flanges, said means for selectively raising andlowering the trough including rigid members carried by the removablefurnace bottom, a plurality of links having a first and asecondposition, the trough being pivotally connected to the links, and abase rockably connected at pivot points on the links, the links in theirfirst position being pivoted on the rigid members at points on the linksintermediate the trough and the base and the links in their secondposition being pivoted not on the rigid members but at the pivot pointson the base, said base being carried by the links in their firstposition clear of the fioor and being lowered onto the floor by thelinks when the links are moved into their second position.

References Cited in the tile of this patent UNITED STATES PATENTS1,698,835 Weiser Jan. 15, 1929 2,489,820 Russell et a1 Nov. 29, 1949FOREIGN PATENTS 80,208 Denmark Nov. 14, 1955 870,157 France Feb. 19,1941

